Low Functional β-Diversity Despite High Taxonomic β-Diversity among Tropical Estuarine Fish Communities

• Published in: PloS one Vol. 7; no. 7; p. e40679
• Main Authors: Villéger, Sébastien, Miranda, Julia Ramos, Hernandez, Domingo Flores, Mouillot, David
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 09.07.2012; Public Library of Science (PLoS)
• Subjects: Animals; Assembly; Biodiversity; Biology; Communities; Community; Community structure; Coral reefs; Ecology; Ecosystem; Ecosystem biology; Ecosystems; Environmental conditions; Environmental gradient; Estuaries; Estuarine environments; Fish; Fishes - classification; Functional groups; Functionally gradient materials; Gulf of Mexico; Models, Statistical; Phylogenetics; Population Dynamics; Salinity; Species composition; Species diversity; Studies; Taxonomy; Tropical Climate; Tropical fish; Vegetation; Gulf of Mexico; France; Austria
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0040679

The concept of β-diversity, defined as dissimilarity among communities, has been widely used to investigate biodiversity patterns and community assembly rules. However, in ecosystems with high taxonomic β-diversity, due to marked environmental gradients, the level of functional β-diversity among communities is largely overlooked while it may reveal processes shaping community structure. Here, decomposing biodiversity indices into α (local) and γ (regional) components, we estimated taxonomic and functional β-diversity among tropical estuarine fish communities, through space and time. We found extremely low functional β-diversity values among fish communities (<1.5%) despite high dissimilarity in species composition and species dominance. Additionally, in contrast to the high α and γ taxonomic diversities, α and γ functional diversities were very close to the minimal value. These patterns were caused by two dominant functional groups which maintained a similar functional structure over space and time, despite the strong dissimilarity in taxonomic structure along environmental gradients. Our findings suggest that taxonomic and functional β-diversity deserve to be quantified simultaneously since these two facets can show contrasting patterns and the differences can in turn shed light on community assembly rules.